Narrative:

A missed communication occurred on takeoff clearance at runway 22L in ord. Double lanes of traffic feeding onto the runway with arrival traffic landing between takeoffs. A lot of chatter on frequency. Tower said what we thought was 'xxy on and hold be ready to go.' I acknowledged with 'xxy on to hold' and was not corrected. We found ourselves waiting in position with an aircraft on short final when all along tower had asked XXX to hurry up and be ready. Tower figured out what had occurred and gave us clearance for takeoff. I feel the overloaded frequency, similar sounding call sign, the received need for haste, all contributed to our mistaking our call sign over another aircraft.

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Original NASA ASRS Text

Title: A B767 CREW, TAXIING FOR TKOF AT ORD, MISINTERPED A TAXI CLRNC AND TAXIED ONTO AN ACTIVE RWY.

Narrative: A MISSED COM OCCURRED ON TKOF CLRNC AT RWY 22L IN ORD. DOUBLE LANES OF TFC FEEDING ONTO THE RWY WITH ARR TFC LNDG BTWN TKOFS. A LOT OF CHATTER ON FREQ. TWR SAID WHAT WE THOUGHT WAS 'XXY ON AND HOLD BE READY TO GO.' I ACKNOWLEDGED WITH 'XXY ON TO HOLD' AND WAS NOT CORRECTED. WE FOUND OURSELVES WAITING IN POS WITH AN ACFT ON SHORT FINAL WHEN ALL ALONG TWR HAD ASKED XXX TO HURRY UP AND BE READY. TWR FIGURED OUT WHAT HAD OCCURRED AND GAVE US CLRNC FOR TKOF. I FEEL THE OVERLOADED FREQ, SIMILAR SOUNDING CALL SIGN, THE RECEIVED NEED FOR HASTE, ALL CONTRIBUTED TO OUR MISTAKING OUR CALL SIGN OVER ANOTHER ACFT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.